1. Field
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to timing control for feedback messages corresponding to downlink data signals in multi-cell wireless networks.
2. Background
Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). The UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), and Time Division-Synchronous Code Division Multiple Access (TD-SCDMA). The UMTS also supports enhanced 3G data communications protocols, such as High Speed Packet Access (HSDPA), which provides higher data transfer speeds and capacity to associated UMTS networks.
As the demand for mobile broadband access continues to increase, research and development continue to advance the UMTS technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications.
One such advancement in UMTS expands high-speed downlink packet access (HSDPA) technology to provide a high-speed downlink channel from each of a plurality of cells, in the same carrier frequency. This system may be referred to as single-frequency dual-cell (SFDC)-HSDPA, or Multipoint HSDPA. Because the SFDC-HSDPA system is newly introduced and the standardization process is ongoing, a number of issues are arising and many solutions are being proposed to address these issues.